1. (a.) Having, or proceeding from, due authority; entitled to obedience, credit, or acceptance; determinate; commanding.

2. (a.) Having an air of authority; positive; dictatorial; peremptory; as, an authoritative tone.

Christian Daedalian absolute absolutist absolutistic accepted accurate acquainted with adept adroit approved apt arbitrary aristocratic armipotent arrogant artistic ascendant assuring at home in at home with attested authentic authenticated authoritarian authorized autocratic binding bossy bravura brilliant canonical cathedral certified charismatic charming circumstantiated clean clever clothed with authority cogent commanding competent conclusive confined confirmed consequential considerable consistent controlling conventional conversant with convictional convincing coordinated correct crack crackerjack cunning customary cute daedal decisive deft dependable despotic determinative dexterous dextrous dictated dictatorial didactic diplomatic doctrinaire documented dogmatic dominant domineering duly constituted dynamic effective effectual efficacious eminent empowered enchanting energetic estimable evangelical ex cathedra ex officio excellent expert factual faithful familiar with fancy feature featured feudal firm forceful forcible formulary good goodish governing graceful great grinding handy hard and fast hegemonic hegemonistic high-handed high-potency high-powered high-pressure high-tension imperative imperial imperious important impressive in force in power indisputable influential informed in ingenious instructive intimate with irrefutable irresistible just knowledgeable lawful leading learned legal legitimate limited literal logical lordly magisterial magistral magnetic mandatory master of masterful masterly mighty mighty in battle momentous monocratic neat no mean of the faith official operative oppressive orthodox orthodoxical overbearing overruling peremptory personable persuasive politic potent powerful preceptive preeminent prepotent prescribed prescript prescriptive prestigious professional proficient proficient in prominent proper proven puissant quick quite some ranking ready received regulation reliable repressive reputable resourceful restricted right rubric ruling sanctioned satisfactory satisfying scholarly scriptural self-consistent senior severe skillful slick solid some sound specialist specialistic specialized standard statesmanlike statutory strict striking strong strong in stylish suasive substantial sufficient superior suppressive supreme sure tactful technical telling textual the compleat the complete totalitarian traditional traditionalistic TRUE true-blue trustable trustworthy truthful tyrannical tyrannous unrefutable up on valid validated verifiable verified veritable